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Chiari Malformation

How Common is Chiari Malformation?

Chiari malformation occurs in about one in every 1,000 births. 

Is Chiari Malformation Hereditary?

There is some evidence that Chiari is hereditary, but this research is still in its early phase.      

What is Chiari Malformation?

Chiari malformation is a condition in which brain tissue extends into the spinal canal. It occurs when the base of the brain, called the cerebellum, protrudes into the upper part of the spinal canal. This can cause a variety of symptoms, including headaches, neck pain, and difficulty with balance. In severe cases, it can also cause numbness, tingling, and weakness in the arms and legs. Chiari malformation can be present at birth or may develop later in life. It is often treated with surgery to correct the malformation and alleviate symptoms. 

When Are You at Risk of Chiari?

There is evidence that Chiari malformation happens more frequently in women than men, and type II Chiari is more prevalent in people of Celtic descent.

There are also certain conditions that can increase the risk of Chiari, such as:

  • Hydrocephalus
  • Tethered cord syndrome
  • Myelomeningocele
  • Syringomyelia
  • Spina bifida

Chiari Types and Symptoms

There are three different types of Chiari malformation, the most common being types I and II.

Type I

Signs and symptoms of Chiari type I typically appear during late childhood or adulthood. People with type I Chiari often experience severe headaches, especially after sudden sneezing, coughing or straining.

Other symptoms of Chiari type I include:

  • Dizziness
  • Numbness and tingling in the hands and feet
  • Neck pain
  • Problems with balance
  • Poor hand coordination
  • Difficulty swallowing, accompanied by gagging, choking and vomiting in some cases

Less common symptoms include:

  • Scoliosis related to spinal cord impairment
  • Weakness
  • Abnormal breathing, like central sleep apnea
  • Ringing or buzzing in the ear
  • Slow heart rhythm

Type II

Type II Chiari is diagnosed when there is a greater amount of tissue that extends into the spinal canal than there would be with type I. Signs and symptoms of type II Chiari can include those related to myelomeningocele, a type of spina bifida. Myelomeningocele occurs when the backbone and spinal cord haven’t closed properly before birth. Chiari type II is typically noted during pregnancy with an ultrasound but can also be diagnosed after birth and in early infancy.

Other signs and symptoms of type II Chiari are:

  • Swallowing problems
  • Weakness in arms
  • Changes in breathing
  • Quick downward eye movements

Type III

Type III Chiari is the most severe type. In type III, a portion of the cerebellum or brain stem extends through an abnormal opening in the back of the skull. Type III is typically diagnosed with an ultrasound during pregnancy or at birth.

This type of Chiari can cause neurological problems and has a higher mortality rate than its counterparts.

Chiari Tests and Diagnosis

In order to diagnose Chiari, your doctor will review your medical history, conduct a physical examination and order an MRI.

Chiari Treatment and Support

Your doctor will recommend Chiari malformation treatment depending on the severity of your condition. Without symptoms, your doctor will likely recommend no treatment aside from regular exams and MRIs.

In order to reduce pressure caused by Chiari, your doctor may recommend posterior fossa decompression surgery. The goal of this surgery is to stop the progression of changes in the brain and spinal canal and stabilize your symptoms. Posterior fossa decompression surgery calls for removing a small section of bone in the back of the skull and upper cervical spine to give the brain more room and relieve pressure.

In some cases, your doctor may also recommend that the dura matter is opened. Dura matter is the covering of the brain. A patch, of either artificial material or tissue gathered from another part of the body, may be sewn onto the dura matter to allow more room for the brain.

You can rest easy knowing that the world-renowned medical staff at Banner Brain & Spine will help you with whatever you and your family need to treat or manage Chiari.